CN102410552B

CN102410552B - Large-scale centralized preparation system for pulverized coal and distribution method

Info

Publication number: CN102410552B
Application number: CN201110282156XA
Authority: CN
Inventors: 车得福; 刘虎; 张留锁; 王欢; 刘银河; 吴松
Original assignee: 西安交通大学
Priority date: 2011-09-21
Filing date: 2011-09-21
Publication date: 2013-12-11
Also published as: CN102410552A

Abstract

The invention discloses a large-scale centralized preparation system for pulverized coal and a distribution method. In the invention, raw coal is dried in a drying system by virtue of heat energy from a power generation enterprise in a raw coal producing area; dried coal briquettes are input into a grinding system so as to be processed into qualified pulverized coal; then the qualified pulverized coal is conveyed to coal-based power enterprises and other pulverized coal users for use by means of conveying equipment; and the whole pulverized coal processing and transportation process is in an inert environment so as to ensure the safe operation of the whole system. The large-scale centralized preparation system and the distribution method are mainly applied to large-scale centralized pulverized coal manufacturing factories in mining areas, wherein the factories provide the pulverized coal for the coal-based power enterprises and other pulverized coal users by a mode of conveying the qualified pulverized coal.

Description

A kind of large-scale concentrative coal powder preparation system and allocator

Technical field:

The invention belongs to the coal electrical domain, relate to a kind of large-scale concentrative coal powder preparation system and allocator safely and efficiently, especially a kind of large-scale coal dust preparation system and allocator of high-efficiency cleaning.

Background technology:

Power industry occupies an important position in Chinese national economy, is the important leverage of the operation of Chinese society economic stability and sustainable development.The important energy industry as China, power industry enterprise in energy-saving and emission-reduction, realize being duty-bound aspect low carbon development.The energy resource structure of China's " rich coal, oil-poor, weak breath ", determined that the coal electricity is still the main force of China's power generation in the following quite a while.Ended for the end of the year 2010,96,219 ten thousand kilowatts of national generating equipment capacities, wherein, 70,663 ten thousand kilowatts of thermoelectricity installed capacitys, account for 73.4% of total installation of generating capacity, determined that 70% multi-source of China's power fuel is in coal.The Eleventh Five-Year Plan period, according to unification of the motherland, require and dispose, power industry is actively pushed forward " above pressing greatly little ", optimizes power supply architecture, fulfils the energy-saving and emission-reduction object of planning ahead of schedule, for significant contribution has been made in the realization of national target for energy-saving and emission-reduction.Simultaneously, because China's coal group of motors net coal consumption rate has approached international most advanced level, the energy-saving and emission-reduction space progressively dwindles, and coal electricity enterprise must complete target for energy-saving and emission-reduction by the innovation of production technology and method.

Tradition coal electricity enterprise fuel means of distribution is: raw coal is transported to the former coal yard of coal electricity enterprise from colliery, send into run coal bin in the fragmentation of former coal yard process coal breaker by coal conveyer belt, send into coal pulverizer by feeder, ground into thin coal dust, coal dust enters cyclone separator under the conveying of hot-air, fine breeze after separated falls into Pulverized Coal Bin, and the fine breeze got off from Pulverized Coal Bin sprays into stove internal combustion by hot-air and fine breeze through burner through machine supplying powder.

There are problems in this traditional production model:

The coal freight charges account for coal electricity enterprise production cost greatly.Coal resources in China mainly concentrates on northwestern, and due to the development pattern of a very long time in past China's electric power in-situ balancing, the coal electricity is built more middle part load center layout eastwards, has formed the energy extensive, the remote conveying coal and has carried general layout.Coal, from the place of production to the power plant, pass through all too many levels such as railway transportation, marine transportation, highway transportation, has further promoted the rise of electric coal price lattice, and the ratio that electric coal freight accounts for cost of electricity-generating is more and more higher, and within 2003 years, the ground such as East China reach more than 50%.Not only the enterprise production and management of coal supply electricity brings white elephant, has also brought transport power anxiety, power plant to lack coal and has shut down the outstanding problems such as appearance repeatedly.According to statistics, 40% and water transport total amount of china railway transportation 30% multiplex in Coal Transport, be one of factor caused railway, water route prerssure on transport.The coal in China transportation range is long, transportation quantity is large, and contains certain moisture, particularly brown coal, and former moisture content of coal can reach 30% left and right, and " fortune water " accounts for a big chunk of freight, causes transport power waste and coal electricity enterprise production cost to improve.

Raw coal adopts the transportation of box open-top car, loss raw coal on the way not only, and serious environment pollution, and safe train operation is threatened.In Coal Transport, during due to train high-speed cruising in transit or meeting, pressure changes former coal particle is splashed, and dust pollution makes Along Railway form one to pollute black-tape, and the crop growth in 50～100m along the line is affected.Particularly at train, enter the porch in tunnel, the coal particles airborne dust and splash even more serious, the coal seam very short time be scattering on circuit just can surpass tread, through train, constantly roll, form reentrainment of dust, train easily reaches the coal dust explosion limit by dust concentration in Shi， tunnel, tunnel, running into naked light can cause an explosion accident, and jeopardizes traffic safety.According to National Development and Reform Committee's statistics, within 2010, china railway coal quantity of shipments completes and approaches 2,000,000,000 tons.By the box open-top car transportation of the railway of national regulation raw coal ullage rate, be 1.2% calculating, only 1 year loss raw coal of ullage is 2,400 ten thousand tons, is equivalent to the year producing coal amount in a large colliery.

Coal electricity enterprise wants the huge pulverized coal preparation system of design and establishing, and capital equipment has coal pulverizer, feeder, mill separator, pulverized-coal collector, machine supplying powder, Powder discharging fan etc.In traditional pulverized-coal fired boiler, it is the pith with the common indivisible combustion system integral body formed of boiler combustion equipment.At present, domestic power plant generally adopts every boiler unit unit pulverized coal preparation system of a set of pulverized coal preparation system of configuration separately.There are problems in existing unit pulverized coal preparation system.

Pulverized coal preparation system is huge, takies a large amount of land resource.Coal electricity enterprise need to set up former coal yard and deposit bunker coal, and will drying loft be set at coal yard, the raw coal feed system install additional remove raw coal in the facility of impurity and disintegrating apparatus etc.

Unit pulverized coal preparation system equipment allowance is higher, has the stock number expense.Owing to generally adopting at present unit pulverized coal preparation system form, every boiler unit configures separately a set of pulverized coal preparation system, coordinates the control relation between unit not tight, and the pulverized coal preparation system initial cost is large, can not large-scale production.In order to guarantee the boiler continuous capacity, the coal pulverizer of every boiler has certain design capacity, by requirement in DL/T5145-2002 " thermal power plant pulverized coal preparation system designing and calculating technical stipulation ", when the coal pulverizer gross capability of design except standby should be not less than boiler maximum continuous rating 110% of Fuel Consumption, except low speed coal mill do not need standby, every boiler of other types coal pulverizer needs standby 1.But China all participates in peak load regulation network than multicomputer at present, whole nation generating set technological cooperation meeting data show, within 2010, national 600MW unit average load coefficient is 73.86%, 300MW unit average load coefficient is 74.2%, except standby, other coal pulverizers can not oepration at full load, and there is the very large wasting of resources in the unit pulverized coal preparation system.

Security and the economy of pulverized coal preparation system and unit are closely related.The pulverized coal preparation system of coal fired power generation unit is huge, condition of work is severe, and fault rate is higher, is one of principal element of the unplanned stoppage in transit of unit, and the safety and economic operation of pulverized coal preparation system directly affects the normal operation of generating set.In coal electricity enterprise's pulverized coal preparation and combustion process, usually run into spontaneous combustion of pulverized coal, blast problem for the high volatile volatile coal, particularly, in bin storage type pulverizing system, because the coal dust conveying is many with the stacking link, pulverized coal preparation system is easy to because spontaneous combustion of pulverized coal sets off an explosion.Although improvement and development along with boiler milling system, heavy duty boiler has substantially all adopted unit pulverized-coal system, reduced the link of coal dust because of the easy spontaneous combustion of stacking state, but still there is the hidden danger of coal dust explosion in pulverized coal preparation system, both damage equipments, the safety of the serious threat person and unit, increased unit outage rate and cost of labor and maintenance cost again.

Pulverized coal preparation system is one of pollution sources of coal electricity enterprise-essential.Pulverized coal preparation system generally leaks out seriously, and dust pollution is serious, and the noise pollution that coal pulverizer produces simultaneously is very large.Once, and the accidents such as blast appear in pulverized coal preparation system, can produce serious environmental pollution.

At coal electricity production cost, day by day increase under the dual-pressure with target for energy-saving and emission-reduction, coal electricity enterprise needs badly and changes the production and operation pattern.

Central milling system refers to workshop or the mill house of setting up one to prepare specially coal dust, first raw coal drier drying, sends into afterwards coal pulverizer and grinds into qualified coal dust.Coal dust is transported to coal electricity enterprise for it by tank car or pneumatic conveying mode.The coal dust that central milling system is produced, except coal supply electricity enterprise is used, provides coal dust can also to the users such as industrial coal powder boiler user, iron and steel enterprise, is the pulverized coal preparation technology of a worth Application and Development.

Overseas power plants is used central milling system to start from the thirties in 20th century.The U.S., in nineteen twenty-seven, in 27 newly-built at that time power plant, has been used 7 covers, with steam or flue gas, raw coal is carried out to drying.Germany's many covers central milling system that come into operation, most steam pipe type driers that adopt.The former Soviet Union is in 30 or 40 years for some central milling systems that also come into operation, and majority is used steam pipe type drier, uses individually the flue gas drum-type.First central milling system is arranged on card Xi Lasike power plant, and nineteen thirty builds up, and within 1932, goes into operation.Process features: raw coal, after the two-stage crushing and screening, is inputted steam pipe type drier, the coal input tipping-bucket hoisting machine after oven dry, and Bed for Fine Coal is mixed input rotary and centrifugal type seperator.The coal dust supported feeds duff pipe with Pneumatic screw pump, borrows compressed air to transport to the boiler compound storehouse.Russia Si Laweiyangsike power plant burns anthracite 800MW boiler unit and has used central milling system, and the employing heating surface is 4000m ²large-scale steam pipe type drier and ball-tube mills, make coal dust and feed coal pipe with Pneumatic screw pump and borrow compressed air delivery to the boiler compound storehouse.The left Luo Fusike burning brown coal 500MW of power plant boiler central milling system, raw coal is input into steam pipe type drier and dries, dry coal is input into Gao Su Hammer and hits the formula coal pulverizer, the dry pulverized coal that weary gas and part are taken out of by drying machine is drawn from discharge chamber, dust-contained airflow enters atmosphere after purifying by multiclone and wet scrubber, coal dust borrows the flue gas-air mixed airflow to bring the separator segregation into, and the coal dust trapped enters the powder storehouse, borrows afterwards pneumatic screw to be pumped to the boiler compound storehouse.

External central milling system also is confined in coal electricity enterprises, and the raw coal transportation link is inevitable, and coal electricity enterprises also must be built former coal yard, huge pulverized coal preparation system, and the dust pollution in enterprise and noise pollution etc. also can't be avoided.

Domestic China Coal Research Institute has carried out certain research to pulverized coal preparation system, patent " a kind of coal dust preparation system and technique " is disclosed, this coal dust preparation system is coal dust preparation system independently, comprise crushing system, drying system and grind system, this system is mainly paid close attention to the preparation process of coal dust, is confined to the front powder process of industrial pulverized coal furnace, does not consider the safety problem in pulverized coal preparation and transportation, though mentioned the problem that needs the outward transport coal dust in patent, but do not considered in detail.Native system is an integral system that utilizes mining area residual heat of electric power plant and flue gas powder process, considered in detail UTILIZATION OF VESIDUAL HEAT IN and powder process and transportation safety issue, the present invention is mainly used in mode by carrying qualified coal dust and provides the concentrated mill house of coal dust for coal electricity enterprise and other coal dusts user.

Summary of the invention:

For the present situation of current electric power enterprise and the problem that central milling system exists, the invention provides a kind of large-scale concentrative coal powder preparation system and allocator safely and efficiently both at home and abroad.

For realizing above-mentioned task; the present invention takes following technical scheme: a kind of large-scale concentrative coal powder preparation system, this system mainly comprises: boiler, steam turbine, generator, condenser, smoke eliminator, condensing heat exchanger, coal breaker, drier, coal pulverizer, wind powder separator, sack cleaner, Pulverized Coal Bin, inert gas reservoir vessel, inertia protection device, coal dust reservoir vessel and coal dust handling facilities.

Described coal breaker connects coal pulverizer by drier, is connected with wind powder separator on coal pulverizer, on wind powder separator, connects respectively Pulverized Coal Bin and sack cleaner; Be connected with smoke eliminator on described boiler, be connected with condensing heat exchanger on smoke eliminator; Described Pulverized Coal Bin connects the coal dust reservoir vessel, and coal dust reservoir vessel inside arranges inertia protection device, and inertia protection device is connected with the inert gas reservoir vessel, and the coal dust reservoir vessel connects the coal dust handling facilities; Described boiler is connected with steam turbine, and steam turbine is connected with generator, and turbine discharge enters condenser.

The flue gas that boiler combustion produces enters smoke eliminator; Flue gas enters the condensing heat exchanger condensation through the smoke eliminator outlet and lowers the temperature to remove the steam in flue gas;

Steam turbine promotes rotation by main steam, drives the generator generating, and turbine discharge enters condenser;

Raw coal is broken for coal cinder in coal breaker, and coal cinder is sent into drier and carried out drying;

Drying source carries out drying to coal cinder in drier, and the first exhaust steam that drier is discharged enters residual heat using device and carries out UTILIZATION OF VESIDUAL HEAT IN;

Dried coal cinder is sent into coal pulverizer and is ground;

The qualified coal dust ground by coal pulverizer enters wind powder separator under the carrying of gas, and the coal dust after separation enters Pulverized Coal Bin, and the second weary gas of being discharged by wind powder separator enters sack cleaner;

Sack cleaner is emptying after further the second weary gas being purified, and the coal dust that sack cleaner is collected enters Pulverized Coal Bin;

The coal dust of Pulverized Coal Bin enters the coal dust reservoir vessel and deposits;

In the coal dust reservoir vessel, inertia protection device is installed, the coal dust reservoir vessel is implemented to inactive protect;

The inert gas reservoir vessel is deposited inert gas;

Described coal dust preparation system mainly provides qualified coal dust outward transport, and this system has been utilized the waste heat of electricity power enterprise; The allocator adopted, guaranteed coal dust transportation feasibility and security, and save raw coal, reduces freight volume, alleviates traffic pressure, and quality of pc can be guaranteed; Concerning coal electricity enterprise, enterprise need not build huge coal dust preparation system, has reduced floor space and station service power consumption rate, increases electricity volume, improves the unit safety economical operation time; Whole delivery process can realize hermetically sealed, reduces transportation and deposits the dust pollution of process enterprise; Can promote effectively the popularization of efficient industrial coal powder boiler, there is great economic benefit and social benefit simultaneously.

The accompanying drawing explanation:

Fig. 1 is a kind of embodiment System Working Principle figure of the present invention;

Fig. 2 is another kind of application example of the present invention;

Wherein: 1 is boiler; 2 is smoke eliminator; 3 is large steam turbine; 4 is generator; 5 is condenser; 6 is coal breaker; 7 is drier; 8 is condensing heat exchanger; 9 is the second heat exchanger; 10 is coal pulverizer; 11 is sack cleaner; 12 is wind powder separator; 13 is Pulverized Coal Bin; 14 is inertia protection device; 15 is the coal dust reservoir vessel; 16 is the inert gas reservoir vessel; 17 is tank car; 18 is the coal dust handling facilities; 19 is small turbine; 20 is air separation unit.

The specific embodiment:

Below in conjunction with accompanying drawing, the present invention is described in further detail:

Shown in Figure 1, its system mainly comprises: boiler, large steam turbine, generator, small turbine, air separation unit, smoke eliminator, condenser, condensing heat exchanger, the second heat exchanger, coal breaker, coal pulverizer, drier, wind powder separator, sack cleaner, Pulverized Coal Bin, coal dust reservoir vessel, inert gas reservoir vessel, inertia protection device, tank car, coal dust handling facilities.Boiler is organized oxygen-enriched combusting, required oxygen is produced by air separation unit, the flue gas that burning produces is successively through entering smoke eliminator after each heating surface, the smoke eliminator outlet is divided into two parts, a part is sent into burner hearth, a part is introduced into condensing heat exchanger condensation cooling, after through the second heat exchanger, enter coal pulverizer after heat temperature raising therein;

Large steam turbine promotes rotation by main steam, drives the generator generating, and large turbine discharge enters condenser;

Air separation unit is driven by small turbine, the nitrogen of its generation passes into the storage of inert gas reservoir vessel, the latent heat of steam in the oxygen sensible heat that absorption is discharged fume through condensing heat exchanger and flue gas, flue-gas temperature is dropped to below dew-point temperature, and the oxygen after heating up enters boiler after mixing with certain proportion with partial fume and organizes oxygen-enriched combusting;

Small turbine is promoted by large extracted steam from turbine, and the small turbine steam discharge enters condenser;

The drying source of drier draws gas from steam turbine, and drying source carries out drying to the raw coal after fragmentation in drier, and the first exhaust steam that drier is discharged enters the second heat exchanger, and heating is through the low-temperature flue gas of condensing heat exchanger cooling;

Dried raw coal is sent into coal pulverizer and is ground, and the flue gas from the second heat exchanger heats up enters coal pulverizer as pumped (conveying) medium and protection gas;

The coal dust sub-fraction of Pulverized Coal Bin is sent into the burning of boiler tissue, and major part enters the coal dust reservoir vessel and deposits, and in the coal dust reservoir vessel, inertia protection device is installed, and guarantees that whole warehouse is under inerting atmosphere;

By the coal dust handling facilities, the coal dust in the coal dust reservoir vessel is discharged in tank car, then is filled with nitrogen and implements inactive protect, guarantee that tank car, under the pressure-fired condition, prevents that air from bleeding.

The course of work of described system is that boiler is organized oxygen-enriched combusting, the large steam turbine of the Steam Actuation of generation, the generating of large steam turbine drive generator.Utilize large extracted steam from turbine to promote small turbine, and then drive air separation unit and produce oxygen and nitrogen, oxygen passes into stove inner tissue oxygen-enriched combusting, and nitrogen enters the inert gas reservoir vessel.Large extracted steam from turbine enters the dry raw coal of drier as drying source, and the first exhaust steam that drier is discharged enters the second heat exchanger and carries out UTILIZATION OF VESIDUAL HEAT IN, and dried raw coal enters coal pulverizer.Entering condensing heat exchanger through the flue gas part purified cools to below acid dew-point temperature and removes remaining sour gas and steam in flue gas, enter afterwards the second heat exchanger and carry out heat temperature raising, grind under the carrying of qualified coal dust flue gas after intensification and enter wind powder separator, the coal dust of separating through wind powder separator enters Pulverized Coal Bin, the second weary gas is through emptying after the sack cleaner dedusting, and the coal dust that sack cleaner is collected enters Pulverized Coal Bin.Coal dust fraction in Pulverized Coal Bin enters boiler and is burnt, and major part enters the coal dust reservoir vessel and stored.Nitrogen is filled with the coal dust reservoir vessel from the inert gas reservoir vessel via inertia protection device, makes coal dust under inert atmosphere, guarantees that it can not blast.The coal dust transportation tank car, after filling coal dust, also is filled with nitrogen, guarantees the security of coal dust transportation.

Referring to Fig. 2, Fig. 2 is another kind of application example of the present invention.With example 1 difference, be, inert gas adopts the flue gas through purifying, the flue gas that boiler combustion produces enters the inert gas reservoir vessel through a part after smoke eliminator and condensing heat exchanger and deposits, and a part enters the coal pulverizer conveying and grinds qualified coal dust after the second heat exchanger heat temperature raising.The flue gas of depositing in the inert gas reservoir vessel carries out inactive protect by inertia protection device to coal dust reservoir vessel and coal dust conveying equipment.

Above content is in conjunction with concrete preferred embodiment further description made for the present invention; can not assert that the specific embodiment of the present invention only limits to this; for the general technical staff of the technical field of the invention; without departing from the inventive concept of the premise; can also make some simple deduction or replace, all should be considered as belonging to the present invention and determine scope of patent protection by submitted to claims.

Claims

1. a large-scale concentrative coal powder preparation system, it is characterized in that, this system mainly comprises: boiler, large steam turbine, generator, condenser, smoke eliminator, condensing heat exchanger, coal breaker, drier, coal pulverizer, wind powder separator, sack cleaner, Pulverized Coal Bin, the inert gas reservoir vessel, inertia protection device, coal dust reservoir vessel and coal dust handling facilities, the drying source of drier carrys out drawing gas of arrogant steam turbine, described coal breaker connects coal pulverizer by drier, be connected with wind powder separator on coal pulverizer, connect respectively Pulverized Coal Bin and sack cleaner on wind powder separator, be connected with smoke eliminator on described boiler, be connected with condensing heat exchanger on smoke eliminator, described Pulverized Coal Bin connects the coal dust reservoir vessel, and coal dust reservoir vessel inside arranges inertia protection device, and inertia protection device is connected with the inert gas reservoir vessel, and the coal dust reservoir vessel connects the coal dust handling facilities, described boiler is connected with large steam turbine, and large steam turbine is connected with generator, and large turbine discharge enters condenser,

Thereby be equipped with in described inert gas reservoir vessel, make coal dust avoid the protection gas of blasting under inert atmosphere, protection gas is flue gas or nitrogen through purifying; When adopting flue gas through purifying as protection gas, the outlet of condensing heat exchanger is divided into two-way, and a road is connected with the entrance of inert gas reservoir vessel, and another road is connected with coal pulverizer after the second heat exchanger heat exchange; When adopting nitrogen as protection gas; the outlet of condensing heat exchanger is connected with coal pulverizer after the second heat exchanger heat exchange; set up air separation unit and carbon dioxide capture device simultaneously; the nitrogen that air separation unit produces passes into the storage of inert gas reservoir vessel; the oxygen that air separation unit produces passes into boiler inner tissue oxygen-enriched combusting, afterbody carbon dioxide capture device capturing carbon dioxide.

2. large-scale concentrative coal powder preparation system as claimed in claim 1 is characterized in that:

Dried coal cinder is sent into coal pulverizer and is ground;

The coal dust of Pulverized Coal Bin enters the coal dust reservoir vessel and deposits.

3. the system as claimed in claim 1, is characterized in that: described boiler employing raw coal, gangue, coal bed gas fuel single fire or multifuel combustion.

4. the system as claimed in claim 1 is characterized in that: hot-air, steam or flue gas that described drier adopts coal electricity enterprise to produce are as drying source.

5. the system as claimed in claim 1 is characterized in that: described coal pulverizer type of drive comprises and adopts driven by power and small steam turbine to drive.

6. the system as claimed in claim 1, it is characterized in that: described smoke eliminator is in order to remove most sour gas, flyash and heavy metal vapor in flue gas.

7. the system as claimed in claim 1, it is characterized in that: the dividing wall type heat exchanger that described condensing heat exchanger adopts resistant material to make, flue gas discharges the latent heat of steam in smoke evacuation sensible heat and flue gas in condensing heat exchanger, and temperature is reduced to below dew-point temperature.

8. the system as claimed in claim 1, is characterized in that: inertia protection device is installed in described coal dust reservoir vessel the coal dust reservoir vessel is implemented to inactive protect.

9. the allocator of a coal dust of producing based on the described system of claim 1; it is characterized in that: the method comprises and adopts railway, highway or water route to seal canned conveying or pipeline pulverized coal conveying to the coal dust user, and tank is filled with inert gas enforcement inactive protect after filling it up with coal dust.